But beyond that, officials investigating a huge dent in the side of the M. Star are still some way off establishing exactly what happened.
Several theories are doing the rounds: The 333-meter-long ship collided with a submarine or a degraded sea mine left over from the Iran-Iraq war; there was an internal explosion; or, most unsettling of all, it was the target of an attack by pirates or terrorists in a strategically vital stretch of water in a sensitive region.
But Mitsui OSK Lines, operator of the world’s second-biggest fleet of oil tankers, was standing by its initial suspicion that the M Star had been “attacked by external sources” as it left the Gulf and entered the Strait of Hormuz, a narrow waterway through which 40 percent of the world’s seaborne oil passes. Japan depends on the Middle East for 90 percent of its oil.
All that the investigation team – which has grown to include the US Navy, maritime authorities from Britain and Japan, a Dubai-based expert on military attacks, and ship operator Mitsui – knows for sure that the cause remains a mystery.
Initially, local reports said the Japan-bound M. Star, laden with 2.3 million barrels of crude oil, had been struck by a freak wave triggered by an earthquake in Iran.
Sea mine or submarine seen as increasingly likely
By Thursday, speculation was growing that the ship had collided with a submarine or a sea mine.
“What we know is that some collision happened,” Capt. Mousa Mourad, a general manager at the United Arab Emirates port of Fujairah, where the M. Star is now moored, told a news conference. “We don’t know what it was. It is possible that it could be a submarine collision, or that it could be a sea mine.”
The collision theory has not dispelled fears that the tanker had been targeted by pirates or terrorists. The scene of the incident lies a few hundred kilometers north of where Somali pirates have hijacked supertankers, including, in April, a South Korean ship bound for the US. The strait has also been identified as a potential target by Al-Qaeda.
Mitsui officials showed pictures of a large square dent on the rear starboard side of the ship’s hull. The explosion – or collision – had also damaged railings, shattered windows, and broken furniture and fittings. News agency photos of the vessels showed that a lifeboat had been blown away on impact.
Crew aboard the M. Star reported seeing a flash, followed by an explosion. One sailor sustained light injuries, but there was no oil leak and the strait remained open for business.